Method and system for robust watermark insertion and extraction for digital set-top boxes

Abstract

Methods and systems for robust watermark insertion and extraction for digital set-top boxes are disclosed and may include descrambling, detecting watermarking messages in a received video signal utilizing a watermark message parser, and immediately watermarking the descrambled video signal utilizing an embedded CPU. The embedded CPU may utilize code that may be signed by an authorized key, encrypted externally to the chip, decrypted, and stored in memory in a region off-limits to other processors. The video signal may be watermarked in a decompressed domain. The enabling of the watermarking may be verified utilizing a watchdog timer. The descriptors corresponding to the watermarking may be stored in memory that may be inaccessible by the main CPU. The watermark may comprise unique identifier data specific to the chip and a time stamp, and may be encrypted utilizing an on-chip combinatorial function.

1. A method for digital media processing, comprising:
 descrambling, in a chip, a received video signal, wherein said chip comprises a main Central Processing Unit (CPU), an embedded CPU, and a watermark message parser; 
 detecting, in said chip, watermarking messages in said descrambled video signal utilizing said watermark message parser; 
 watermarking, in said chip, said video signal immediately following said descrambling utilizing said embedded CPU according to said detected watermarking messages, said watermarking messages including a time indicator and a unique identifier data utilizing an on-chip combinatorial function specific to said chip; and 
 storing, in said chip, said watermarked video signal only in memory that is inaccessible by said main CPU. 
 
     
     
       2. The method according to  claim 1 , comprising:
 utilizing, by said embedded CPU, code that is signed by an authorized key. 
 
     
     
       3. The method according to  claim 2 , wherein the utilizing comprises:
 utilizing said code for said embedded CPU that is not visible to other processors. 
 
     
     
       4. The method according to  claim 2 , wherein the utilizing comprises:
 encrypting and decrypting said code for said embedded CPU externally to said chip; and 
 storing said code in memory only in a region that is inaccessible to other processors. 
 
     
     
       5. The method according to  claim 1 , wherein the watermarking comprises:
 watermarking said video signal in a decompressed domain. 
 
     
     
       6. The method according to  claim 1 , further comprising:
 verifying whether said watermarking is enabled utilizing a watchdog timer. 
 
     
     
       7. The method according to  claim 1 , further comprising:
 storing descriptors corresponding to said watermarking only in memory that is inaccessible by said main CPU. 
 
     
     
       8. The method according to  claim 1 , further comprising:
 inserting said watermark messages in said received video signal at a head-end which generates said received video signal prior to encryption. 
 
     
     
       9. The method according to  claim 8 , wherein the inserting comprises:
 encrypting said inserted watermark messages using a unique algorithm. 
 
     
     
       10. The method according to  claim 9 , further comprising:
 removing said inserted watermark messages immediately following said detecting of said watermark messages by said watermark message parser. 
 
     
     
       11. A system for digital media processing, comprising:
 a circuit in a chip comprising a main Central Processing Unit (CPU), an embedded CPU, and a watermark message parser; 
 said circuit being configured to:
 descramble a received video signal; 
 detect watermarking messages in said descrambled video signal utilizing said watermark message parser; 
 watermark said video signal immediately following said descrambling utilizing said embedded CPU according to said detected watermarking messages, said watermarking messages including a time indicator and a unique identifier data utilizing an on-chip combinatorial function specific to said chip; and 
 store said watermarked video signal only in memory that is inaccessible by said main CPU. 
 
 
     
     
       12. The system according to  claim 11 , wherein said embedded CPU utilizes code that is signed by an authorized key. 
     
     
       13. The system according to  claim 12 , wherein said code for said embedded CPU is not visible to other processors. 
     
     
       14. The system according to  claim 12 , wherein said code for said embedded CPU is encrypted externally to said chip, decrypted, and stored in memory only in a region that is inaccessible to other processors. 
     
     
       15. The system according to  claim 11 , wherein said circuit is further configured to watermark said video signal in a decompressed domain. 
     
     
       16. The system according to  claim 11 , wherein said circuit is further configured to verify whether said watermarking is enabled utilizing a watchdog timer. 
     
     
       17. The system according to  claim 11 , wherein said circuit is further configured to store descriptors corresponding to said watermarking only in memory that is inaccessible by said main CPU. 
     
     
       18. The system according to  claim 11 , wherein said watermark messages in said received video signal are inserted at a head-end which generates said received video signal prior to encryption. 
     
     
       19. The system according to  claim 18 , wherein said inserted watermark messages are encrypted using a unique algorithm. 
     
     
       20. The system according to  claim 11 , wherein said circuit is further configured to remove said inserted watermark messages immediately following said detecting of said watermark messages by said watermark message parser. 
     
     
       21. A method for digital media processing, comprising:
 conditional access (CA) descrambling, in a chip, a received video signal, wherein said chip comprises a main Central Processing Unit (CPU), an embedded CPU and a watermark message parser; 
 detecting, in said chip, watermarking messages in said CA descrambled video signal utilizing said watermark message parser; 
 watermarking, in said chip, said CA descrambled video signal utilizing said embedded CPU according to said detected watermarking messages, said watermarking messages including a time indicator and a unique identifier data utilizing an on-chip combinatorial function specific to said chip; 
 copy protecting (CP) scrambling, in said chip, said watermarked video signal; and 
 storing, in said chip, said CP scrambled video signal only in memory that is inaccessible by said main CPU.